CANNABINOIDS and HALLUCINOGENS

Transcription

1 CANNABINOIDS and HALLUCINOGENS

2 Cannabinoids

3 Cannabis Most popular recreational drug in the US after alcohol and tobacco Possession and use illegal under federal law, but states have variable policies on enforcement and prosecution Schedule I

4 Medical Marijuana Alleged efficacy in treating: AIDS (HIV) & AIDS Wasting Diseases Arthritis Crohn's Disease Epilepsy / Seizures Glaucoma Migraines Multiple Sclerosis / Muscle Spasms Nausea cf Chemotherapy Pain / Analgesia

5 Chemistry Various parts of the plant differ in chemical composition Sinsemilla seedless, unfertilized flowering tops of female cannabis plants THC is found in the plant s flowering or fruity tops, leaves and resin

6 Cannabinoid Receptors 1964 Gaoni and Mechoulam identify structure of THC 1990 s CB 1 and C are identified and characterized CB 1 : expressed mostly at nerve terminals, mediate neurotransmitter release CB 2 : immunomodulation (eicosanoids)

7 Mechanism of Action THC is thought to stimulate reward circuits in the brain and to act as a dopamine agonist THC in marijuana can bind with cannabinoid receptors located on the presynaptic and/or postsynaptic cell in a synapse

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9 Effects A mixture of depressant and stimulant effects is noted at low doses CNS depressant at high doses The endogenous cannabinoid system, which consists of cannabinoid neurotransmitters, receptors, metabolic enzymes and transporters affect physiological and behavioral processes

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11 Cannabinoid Pharmacokinetics Smoked THC Time-Concentration Curve THC concentrations fall: To about 60% of their peak within 15 minutes after the end of smoking. To about 20% of their peak 30 minutes after the end of smoking. Courtesy Marilyn Huestis, Borkenstein Drug Course, 2012

12 Metabolism

13 Pharmacokinetics THC is rapidly absorbed and distributed to tissues Counterclockwise hysteresis Delay between the effects and plasma THC concentrations THC can be measured w/in seconds of inhalation Concentrations increase rapidly

14 Oral Administration THC and 11-OH THC concentrations are much lower as compared to smoked administration Degradation in the stomach and significant first-pass metabolism in the liver Two THC peaks may be observed enterohepatic circulation The onset, magnitude, and duration of effects general occur later The effects are lessened

15 Distribution Large V d 97-99% of the drug is bound to plasma proteins Highly perfused organs are rapidly exposed to the drug Highly lipid soluble Slow release of the drug from fat and significant enterohepatic circulation long drug half-life

16 Chemistry THC decomposes when exposed to air, heat or light Exposure to acid can oxidize THC to cannabinol

17 Hallucinogens

18 What are they? Hallucinogens are a diverse group of drugs that alter perception (awareness of surrounding objects and conditions), thoughts, and feelings. They cause hallucinations, or sensations and images that seem real though they are not. Hallucinogens can be found in some plants and mushrooms (or their extracts) or can be human-made. People have used hallucinogens for centuries, mostly for religious rituals.

19 Hallucinogens Hallucinogens LSD Salvia Divinorum Peyote Mescaline Psilocybin Dissociatives PCP Dextromethorphan (high doses) Ketamine

20 Substance Induced Intoxication (DSM IV) Psychosis A loss of contact with reality Hallucinations Auditory, visual, tactile Delusional beliefs Lack of insight, paranoia Disorganized thought Pressure of speech, flight of ideas Personality changes Mania

21 Lysergic Acid Diethylamide (LSD) O CH 2 CH 3 H C N CH 2 CH 3 N H CH 3 N H d-isomer LSD-25, Acid, Microdot, White Lightning

22 LSD Metabolism OH O CH 3 CH 2 N C H LAE N CH 3 NH O CH 3 CH 2 N C CH 3 CH 2 14-hydroxy-LSD N CH 3 OH NH O CH 3 CH 2 N C CH 3 CH 2 13-hydroxy-LSD N CH 3 NH CH 3 CH 2 HO CH 2 CH 2 N O C NH CH 3 CH 2 CH 3 CH 2 N O C NH CH 3 CH 2 CH 3 CH 2 N O C NH N-hydroxyethyl-LSD N CH 3 LSD N CH 3 norlsd N H Other Metabolites CH 3 CH 2 N O C CH 3 CH 2 N O C CH 3 CH 2 NH CH 3 CH 2 NH 2-oxo-3-hydroxy-LSD N CH 3 OH O? 2-oxo-LSD N CH 3 O Copy right 2003

23 LSD Albert Hofmann working for Sandoz Pharmaceutical, synthesizes LSD Hofmann accidental exposed to LSD I suddenly became strangely inebriated. The external world became changed as in a dream. Objects appeared to gain in relief; they assumed unusual dimensions; and colors became more glowing. Even self-perception and the sense of time were changed. When the eyes were closed, colored pictures flashed past in a quickly changing kaleidoscope. After a few hours, the not unpleasant inebriation, which had been experienced whilst I was fully conscious, disappeared.. What had caused this condition? - - Albert Hofmann - - Laboratory Notes (1943)

24 LSD - Dose and Effect Normally micrograms Minimal clinical perceptible dose is 20 or 25 micrograms Much lower than in the 1960 s Duration and intensity are dose dependent Effect duration typically 6-12 hours

25 LSD Effects PERCEPTUAL Altered shapes and colors, visual hallucinations, distorted time sense, synesthesia SOMATIC Dizziness, weakness, tremors, nausea, tingling of skin, blurred vision COGNITIVE Large and rapid mood changes, difficulty thinking, de-personalization, dream-like feeling, trance-like state

26 LSD Effects Wikipedia LSD-25

27 LSD Pharmacology High affinity for pre and post synaptic serotonin receptors 5-HT 2 partial agonist/antagonist Inhibition of serotonergic effects in the Raphe Nuclei implicated in sensory effects Some affinity for dopamine and NE receptors systems also

28 LSD Pharmacokinetics Duration of effect 6-12 hours Following a 140 mcg dose Peak plasma concs of 5 1 hour Half life 3-4 hours Death attributed to LSD Postmortem blood concentration 5 ng/ml

29 PCP - Phencyclidine Angel Dust Embalming fluid Sherm/Shermans Killer weed Sernyl Wet Fry

30 Phencyclidine - PCP Dissociative anesthetic Effects include emergent delirium Possesses both stimulant and depressant properties Can produce hallucinations

31 Phencyclidine Receptor Chemistry PCP 2 receptor Part of dopamine reuptake transporter? PCP 1 receptor Part of NMDA complex

32 PCP - Effects on Behavior User reported depressant effects Calmness, depression, psychic numbing, anergia, impaired concentration, ataxia, sedation, analgesia Enhances alcohol and barbiturate effects User reported stimulant effects Feelings of euphoria, power, strength, invulnerability, anxiety, insomnia, anorexia. BP, Heart Rate, temperature increase User reported hallucinogenic effects Slowed time perception, visual illusions, paranoia, religious experiences, bizarre behavior

33 PCP Dose and Pharmacokinetics Typical street doses are 3-5 mg Laced cigarettes or marijuana cigarettes Up to 50 mg PCP PCP is well absorbed Highly lipophilic and protein binding is 65% ½ life: 7-46 hrs (Avg. 21 hrs.) Peak plasma levels: 1-4 hrs Rapidly enters brain, elimination from brain slower than blood

34 PCP Pharmacodynamics Peak effects are route dependent Smoking 1 min Inhalation Several min Oral min Duration of effects Typical street high: 4-6 hr Subjective effects: hr

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